A steam power plant typically comprises a steam generator and a pressure series of steam turbines wherein the steam conditions of the first steam turbine inlet is dependent upon the actual condition of the steam generators. While steam generator and steam turbine performance can be initially matched to provide optimum performance, overtime the performance of the steam generator typically deteriorates resulting in lower steam pressure at the steam turbine for a given thermal load. It is further possible that the plant may be operated at a higher thermal load than initially designed. Both these circumstances may lead to a need for increased swallowing capacity. A way to solve this problem is to initially define a high swallowing capacity of the steam turbine. However, if the steam turbine is initially designed to have a high swallowing capacity, during initial, operation significant throttling of the turbine control valves could be required resulting in a loss of plant efficiency. There is therefore a need to seek an alternative.